On the use of Pilot-Assisted Matched Filtering in UWB Time-Interleaved Sampling

A software defined radio for ultra wideband (UWB) communication systems places several stringent requirements on the analog-to-digital converter (ADC). In particular, the ADC must have sufficiently high sampling frequency-typically on the order of several gigasamples per second-to accurately reconstruct the received UWB pulse. An alternative approach to using a single expensive ADC with the above features is to sample the received signal with an array of lower speed ADCs driven by time-interleaved (TI) sampling clocks, allowing the array to operate as if it were a single ADC with a much higher effective sampling frequency. However, ADC timing, gain and offset mismatches represent significant design challenges in such architectures. In this paper, we investigate the use of a pilot-based matched-filter architecture in mitigating the impact of ADC gain, offset, and timing mismatches. The analytical results derived in this paper (a) demonstrate the efficacy of a pilot-based matched filter in mitigating the impact of timing mismatch errors on a TI-ADC array, and (b) allow for the design specification of the number of pilots required in order to achieve desired system performance